Dual-band antenna and communication equipment

Abstract

The utility model provides a dual-band antenna and a communication device, the dual-band antenna comprises a first antenna and a second antenna which are arranged adjacently, the working frequency of the first antenna is greater than that of the second antenna, the first antenna is a full-wave dipole antenna, the first antenna comprises two first branches, and the first branches are connected with the second branch. The first antenna comprises two first branches, a first feeding point is arranged between the two first branches, the second antenna comprises two second branches, a second feeding point is arranged between the two second branches, and a guide opening for reducing the reflection effect of the second antenna on the first antenna is arranged between the two second branches. According to the dual-band antenna and the communication equipment provided by the utility model, the reflection effect of the second antenna at a high frequency band can be weakened through the arrangement of the guide opening, so that the omni-directivity of a directional diagram is better, and the average gain of a horizontal plane is improved. Moreover, the dual-band antenna does not use a mode cancelling dual-band antenna, so that the frequency band span of the dual-band antenna can be larger, and the dual-band antenna is not limited by modes.

Description

Technical Field

[0001] The utility model belongs to the technical field of antennas, and more specifically, relates to a dual-band antenna and communication equipment. Background Art

[0002] The dual-band dual-fed antenna can save circuit boards and combiners by setting two antennas on the same circuit board, thus reducing material and assembly costs. The current dual-band dual-fed antennas are various types of mode cancellation antennas. Antennas designed based on mode cancellation have two main disadvantages: 1) The antenna ports are basically set on both sides of their radiation center, which will cause the radiation pattern of the antenna to shift toward the feeding side, resulting in a decrease in the performance index of the average gain in the horizontal plane; 2) Since the current distribution on the antenna surface is closely related to the antenna operating frequency band, this method is not applicable to two antennas with a larger frequency span, such as 2.4G antennas and 5G antennas. Utility Model Content

[0003] The purpose of the embodiments of the utility model is to provide a dual-band antenna and communication equipment to solve the technical problems existing in the prior art that the average horizontal gain is low and cannot be applied to antennas with a larger frequency span.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to provide a dual-band antenna, including a first antenna and a second antenna arranged adjacent to each other, the operating frequency of the first antenna is greater than the operating frequency of the second antenna, the first antenna is a full-wave dipole antenna, the first antenna includes two first branches, and the first feeding point is between the two first branches, the second antenna includes two second branches, and the second feeding point is between the two second branches, and there is a leading opening between the two second branches to reduce the reflection effect of the second antenna on the first antenna.

[0005] Optionally, the dual-band antenna has a symmetry line, the symmetry line passes through two first branches and two second branches, and the first antenna and the second antenna are both symmetrically arranged about the symmetry line.

[0006] Optionally, the first branch has a first cutoff opening, so that the first branch is divided into a first microstrip line and a second microstrip line that are arranged at intervals, and two of the second microstrip lines are arranged adjacent to each other.

[0007] Optionally, a side of the second microstrip line close to the first feeding point has a first gap.

[0008] Optionally, the first slot extends along a length direction of the first antenna.

[0009] Optionally, an end of the second microstrip line close to the first microstrip line is the first end of the second microstrip line, the distance between the first ends of two second microstrip lines is a first dimension, the length of the leading opening is a second dimension, and the ratio of the first dimension to the second dimension is 0.7 to 1.3.

[0010] Optionally, a second slit is formed on a side of the second branch close to the guide opening.

[0011] Optionally, an end of the second branch away from the guide opening has a choke structure, the choke structure extends along the length direction of the second antenna, and a choke gap is formed between the choke structure and the second branch.

[0012] Optionally, an end of the second branch near the guide opening extends toward the choke structure to form an extension portion, and a side of the extension portion away from the choke gap is flush with a side of the choke structure away from the choke gap.

[0013] The utility model also provides a communication device, comprising the above-mentioned dual-band antenna.

[0014] The beneficial effects of the dual-band antenna and communication equipment provided by the utility model are as follows: compared with the prior art, the dual-band antenna of the utility model includes a first antenna and a second antenna with different frequency bands, and the first antenna is a full-wave dipole antenna, which can enhance the basic gain of the high-frequency antenna, thereby improving the average gain of the horizontal plane. There is a guide opening between the two second branches of the second antenna. When working at a high frequency, the second antenna is equivalent to a reflection strip for the first antenna. The setting of the guide opening can weaken the reflection effect of the second antenna in the high frequency band, so that the omnidirectionality of the directional diagram is better, and the average gain of the horizontal plane is improved. Moreover, by respectively setting the feeding points of the first antenna and the second antenna at their corresponding antenna branches, and not using a dual-band antenna with mode cancellation, the frequency band span of the dual-band antenna can be larger and not restricted by the mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A schematic diagram of the structure of a first dual-band antenna provided by an embodiment of the utility model;

[0017] Figure 2A schematic diagram of the structure of the first second branch provided in an embodiment of the utility model;

[0018] Figure 3 A schematic diagram of the structure of a second dual-band antenna provided by an embodiment of the utility model;

[0019] Figure 4 A schematic diagram of the structure of the second branch provided by the embodiment of the utility model;

[0020] Figure 5 for Figure 1 A graph of the S parameters of the dual-band antenna;

[0021] Figure 6 for Figure 3 A graph of the S parameters of the dual-band antenna;

[0022] Figure 7 for Figure 3 Schematic diagram of the dual-band antenna pattern.

[0023] Among them, the reference numerals in the figure are:

[0024] 10-first antenna; 11-first branch; 111-first microstrip line; 112-second microstrip line; 1121-first gap; 113-first cut-off point; 12-first feeding point; 20-second antenna; 21-second branch; 211-second gap; 22-second feeding point; 23-choke structure; 24-choke gap; 25-extension; 26-lead opening; 30-dielectric plate. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0027] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] The dual-band dual-fed antenna saves circuit boards and eliminates combiners by placing two antennas on the same circuit board, thereby reducing material and assembly costs. The current dual-band dual-fed antennas are various types of mode cancellation antennas. Antennas designed based on mode cancellation have two main disadvantages: 1) The antenna ports are basically set on both sides of their radiation center, which will cause the radiation pattern of the antenna to shift toward the feeding side, resulting in a decrease in the performance index of the average gain in the horizontal plane; 2) Since the current distribution on the antenna surface is closely related to the antenna operating frequency band, this method is not applicable to two antennas with a larger frequency span, such as 2.4G antennas and 5G antennas.

[0030] In order to alleviate the above technical problems, the utility model proposes a dual-band antenna and communication equipment.

[0031] The dual-band antenna provided in the embodiment of the utility model is now described.

[0032] Please also read Figures 1 to 4 , the dual-band antenna includes a first antenna 10 and a second antenna 20 that are adjacently arranged, and the operating frequency of the first antenna 10 is greater than the operating frequency of the second antenna 20. For the sake of convenience, the operating frequency of the first antenna 10 is referred to as a high frequency, and the operating frequency of the second antenna 20 is referred to as a low frequency. The low frequency and the high frequency are relative to each other and do not limit the specific frequency of the antenna. The higher the operating frequency, the smaller its electrical length, and the lower the operating frequency, the larger its electrical length. Accordingly, the electrical length of the first antenna 10 is smaller than the electrical length of the second antenna 20. Among them, the operating frequency can be understood as the center frequency when the antenna is working, and can also be understood as the frequency band when the antenna is working. The frequency band when the first antenna 10 is working does not overlap with the frequency band when the second antenna 20 is working, and the operating frequency bands of the first antenna 10 and the second antenna 20 have a large span.

[0033] The first antenna 10 is a full-wave dipole antenna, which can make better use of the board space compared to a half-wave dipole antenna. Since the full-wave dipole antenna has a longer current path and more in-phase current superposition, it can improve the basic gain of the first antenna 10 compared to a half-wave dipole antenna, thereby improving the average gain in the horizontal plane. The first antenna 10 includes two first branches 11, and a first feeding point 12 is between the two first branches 11, that is, the first antenna 10 is fed between the two first branches 11, one end of the feeding structure is connected to one of the first branches 11, and the other end of the feeding structure is connected to the other first branch 11.

[0034] The second antenna 20 includes two second branches 21, and a second feeding point 22 is provided between the two second branches 21, that is, the second antenna 20 is fed between the two second branches 21, one end of the feeding structure is connected to one of the second branches 21, and the other end of the feeding structure is connected to the other second branch 21. The first antenna 10 and the second antenna 20 respectively have feeding points, and the first antenna 10 and the second antenna 20 are fed respectively.

[0035] There is a guide opening 26 between the two second branches 21, and the guide opening 26 is used to reduce the reflection effect of the second antenna 20 on the first antenna 10. In the low frequency band, the electrical size of the first antenna 10 is small, and it will not produce a more obvious reflection effect on the second antenna 20, so the radiation pattern of the second antenna 20 can basically maintain horizontal omnidirectionality. However, in the high frequency band, the electrical size of the second antenna 20 is large, which is equivalent to a reflection strip for the first antenna 10, which will cause the radiation pattern of the first antenna 10 to shift away from the second antenna 20, resulting in a decrease in the average gain in the horizontal plane. By increasing the distance between the two second branches 21 in the second antenna 20, that is, by opening the guide opening 26, electromagnetic waves can be transmitted through the guide opening 26, thereby weakening the reflection effect of the second antenna 20 in the high frequency band, and making the omnidirectionality of the radiation pattern of the first antenna 10 better.

[0036] The dual-band antenna in the above embodiment includes a first antenna 10 and a second antenna 20 with different frequency bands. The first antenna 10 is a full-wave dipole antenna, which can enhance the basic gain of the high-frequency antenna, thereby improving the average gain of the horizontal plane. There is a guide opening 26 between the two second branches 21 of the second antenna 20. When working at a high frequency, the second antenna 20 is equivalent to a reflection strip for the first antenna 10. The setting of the guide opening 26 can weaken the reflection effect of the second antenna 20 in the high frequency band, making the omnidirectionality of the radiation pattern better and improving the average gain of the horizontal plane. Moreover, by setting the feeding points of the first antenna 10 and the second antenna 20 at their corresponding antenna branches respectively, and not using a dual-frequency dual-feed antenna with mode cancellation, the frequency band span of the dual-band antenna can be larger and not restricted by the mode.

[0037] In some embodiments of the present invention, please refer to Figures 1 to 4 , the two first branches 11 extend along the first direction, and the two second branches 21 also extend along the first direction, that is, the length direction of the first antenna 10 and the length direction of the second antenna 20 are parallel to each other. In this way, the directional patterns of the first antenna 10 and the second antenna 20 can be symmetrically arranged. The first antenna 10 and the second antenna 20 are arranged along the second direction, and the first direction can be perpendicular to the second direction or nearly perpendicular to each other to ensure a small volume of the dual-band antenna.

[0038] In some embodiments of the present invention, please refer to Figure 1 and Figure 3 The first antenna 10 and the second antenna 20 are located on the same dielectric plate 30 and can be formed on the surface of the dielectric plate 30 by copper plating or the like. By arranging the first antenna 10 and the second antenna 20 on the same dielectric plate 30, the two antennas can be processed and formed at one time, and the installation of the dual-band antenna is also more convenient.

[0039] In some embodiments of the present invention, the first antenna 10 is a 5G antenna, and the second antenna 20 is a 2.4G antenna. The 2.4G antenna and the 5G antenna are commonly used frequency band antennas.

[0040] In some embodiments of the present invention, please refer to Figure 1 and Figure 3 The dual-band antenna has a symmetry line, which passes through the two first branches 11 and the two second branches 21. When the second direction is perpendicular to the first direction, the symmetry line is arranged parallel to the second direction. The first antenna 10 and the second antenna 20 are both arranged symmetrically about the symmetry line, and the midpoint of the first antenna 10 and the midpoint of the second antenna 20 are both located on the symmetry line. In this way, the directional patterns of the first antenna 10 and the second antenna 20 can be arranged symmetrically, and the radiation energy in all directions can be more evenly distributed.

[0041] In some embodiments of the present invention, please refer to Figure 1 and Figure 3 , the first branch 11 has a first truncation 113, so that the first branch 11 is divided into a first microstrip line 111 and a second microstrip line 112 that are spaced apart, and the two second microstrip lines 112 are arranged adjacent to each other. By setting the first truncation 113, the first branch 11 is divided into two relatively independent structures, namely the first microstrip line 111 and the second microstrip line 112. Both of the two first branches 11 have a first truncation 113, and the two second microstrip lines 112 formed are arranged adjacent to each other. When feeding the first antenna 10, one end of the feeding structure is connected to one of the second microstrip lines 112, and the other end is connected to the other second microstrip line 112.

[0042] Due to the characteristics of the even-order mode of the full-wave dipole antenna, the current direction will be deflected at the center of the antenna, and it is difficult to excite it. In this embodiment, by setting the first truncation opening 113, a capacitance effect is formed at the first truncation opening 113, so that in the same first branch 11, most of the currents on the first microstrip line 111 and the second microstrip line 112 are in phase, achieving in-phase superposition of the currents, thereby achieving effective excitation of the full-wave dipole antenna.

[0043] In some embodiments of the present invention, please refer to Figure 1 and Figure 3 , the second microstrip line 112 has a first slot 1121 on one side close to the first feeding point 12. The first slot 1121 is located at one end of the second microstrip line 112 close to the first feeding point 12, where the current is relatively large. By setting the first slot 1121 here, the current distribution on the second microstrip line 112 can be more effectively changed, so that the second microstrip line 112 and the first microstrip line 111 have more currents in the same direction. Due to the characteristics of the even-order mode of the full-wave dipole antenna, the current direction will be deflected at the center of the antenna, and it is difficult to excite it. The first slot 1121 can change the direction of the current, thereby achieving effective excitation of the full-wave dipole antenna.

[0044] In some embodiments, the first slot 1121 extends along the length direction of the first antenna 10, that is, the first slot 1121 is in the shape of a long strip, and separates the portion of the second microstrip line 112 close to the first feeding point 12 into two metal strips. When the first antenna 10 is fed at the first feeding point 12, the current is concentrated at the two metal strips, which increases the electrical length of the second microstrip line 112 and further improves the antenna gain of the first antenna 10.

[0045] Optionally, the first slot 1121 is located at the center of the first antenna 10 in the width direction thereof, so that the structure of the first antenna 10 is symmetrical in the second direction (left-right symmetrical), and the symmetry of the radiation pattern is better.

[0046] In some embodiments of the present invention, please refer to Figure 1 and Figure 3 , the end of the second microstrip line 112 close to the first microstrip line 111 is the first end of the second microstrip line 112, the distance between the first ends of the two second microstrip lines 112 is the first dimension, the length of the lead-in opening 26 is the second dimension, and the ratio of the first dimension to the second dimension is 0.7 to 1.3. The second microstrip lines 112 of the two first branches 11 are arranged adjacent to each other, the end of the second microstrip line 112 away from the first feeding point 12 is the first end of the second microstrip line 112, the end of the second microstrip line 112 close to the first feeding point 12 is the second end of the second microstrip line 112, and the distance between the first ends of the two second microstrip lines 112 is the first dimension. The length direction of the lead-in opening 26 is the length direction of the second antenna 20, and the dimension of the lead-in opening 26 in the length direction of the second antenna 20 is the second dimension.

[0047] When the ratio of the first dimension to the second dimension is too small, the length of the leading opening 26 is too small, which will cause the second antenna 20 to reflect the first antenna 10, and the radiation pattern of the first antenna 10 is set to the left. When the ratio of the first dimension to the second dimension is too large, firstly, the distance between the two second branches 21 of the second antenna 20 is too large, making it difficult to feed power, and secondly, the size of the second antenna 20 in the first direction is too large, which is not conducive to the miniaturization of the antenna. Therefore, the ratio of the first dimension to the second dimension is set to 0.7 to 1.3, such as 0.9, 1, 1.2, 1.3, etc.

[0048] In some embodiments of the present invention, please refer to Figure 2 In the second antenna 20, a second slit 211 is provided on the side of the second branch 21 close to the guide opening 26. The side of the second branch 21 close to the guide opening 26 is the side of the second branch 21 close to the second feeding point 22. The closer to the feeding point, the greater the current intensity, and the easier it is for the electromagnetic waves transmitted from the first antenna 10 to the second antenna 20 to be reflected. The farther away from the feeding point, the smaller the current intensity, and the smaller the impact on the first antenna 10. By setting the second slit 211, the effective area of ​​the metal part of the second branch 21 close to the guide opening 26 can be made smaller, and the impact on the first antenna 10 is reduced without reducing the electrical length of the second branch 21.

[0049] In some embodiments, the length direction of the second slit 211 is the same as the length direction of the second antenna 20, and the second slit 211 extends from the side of the second branch 21 close to the second feeding point 22 toward the direction away from the second feeding point 22. In other words, the second slit 211 is in the shape of a long strip, and the metal parts on both sides of the second slit 211 are also in the shape of strips, so that the current of the metal part is distributed along the length direction of the second antenna 20.

[0050] In some embodiments of the present invention, please refer to Figure 3 and Figure 4 The end of the second branch 21 away from the guide opening 26 has a choke structure 23, which extends along the length direction of the second antenna 20 and extends toward the guide opening 26, and a choke gap 24 is formed between the choke structure 23 and the second branch 21. The end of the second branch 21 away from the guide opening 26 is the end of the second antenna 20 in its length direction, and the length direction of the choke structure 23 is parallel to the length direction of the second antenna 20, so that the choke structure 23 is arranged adjacent to the body of the second branch 21 to form the choke gap 24.

[0051] By providing the choke gap 24 , the energy radiated by the first antenna 10 and received by the second antenna 20 can be trapped there, thereby improving the isolation between the first antenna 10 and the second antenna 20 .

[0052] Optionally, the length of the choke slot 24 is half the wavelength of the first antenna 10, which can further improve the choke effect of the choke slot 24. The length of the choke slot 24 is its dimension in the length direction of the second antenna 20.

[0053] In some embodiments, the end of the second branch 21 away from the leading opening 26 is called the second end of the second branch 21, and the opposite sides of the second end of the second branch 21 ( Figure 3 A choke structure 23 is provided on both sides (left and right sides), and a choke gap 24 is formed on the opposite sides of the second branch 21, which can trap the energy radiated by the first antenna 10 received by the second antenna 20 on the opposite sides of the second branch 21, thereby improving the isolation between the first antenna 10 and the second antenna 20.

[0054] In some embodiments of the present invention, please refer to Figure 4 , one end of the second branch 21 close to the guide opening 26 extends toward the choke structure 23 to the choke structure 23, and extends to form an extension portion 25, and the side of the extension portion 25 away from the choke slot 24 is arranged flush with the side of the choke structure 23 away from the choke slot 24. One end of the second branch 21 close to the guide opening 26 extends toward the choke structure 23, that is, extends along the length direction of the second branch 21 to form an extension portion 25, and the extension portion 25 is arranged adjacent to one end of the choke structure 23. The arrangement of the extension portion 25 makes full use of the remaining space on the dielectric plate 30, and the structure is more compact while maintaining the gain of the second antenna 20. The side of the choke structure 23 away from the choke slot 24 is arranged flush with one side of the second branch 21, firstly, the volume of the second antenna 20 can be reduced, the distance between the first antenna 10 and the second antenna 20 can be further increased, and the isolation can be improved; secondly, the performance degradation caused by the interlacing of the feed line and the choke structure 23 can be avoided in actual use.

[0055] In order to verify the effect of the choke structure 23, Figure 1 and Figure 3 The antenna in the model is simulated and the Figure 5 and Figure 6 ,contrast Figure 5 and Figure 6 S 12 It can be seen from the curve that in the 5 GHz to 6 GHz frequency band, the isolation between the first antenna 10 and the second antenna 20 is significantly improved.

[0056] In order to verify the performance of the dual-band antenna proposed in this utility model, Figure 3 The antenna in the model is simulated and the Figure 7 , Figure 7 The three curves in FIG. 1 are the directional patterns of the antenna in the frequency bands of 2.45 GHz, 5.2 GHz and 5.8 GHz respectively. The first antenna 10 is less affected by the reflection of the second antenna 20, and the directional pattern does not deviate in a certain direction.

[0057] The utility model also provides a communication device, the communication device includes the dual-band antenna in any of the above embodiments. The communication device can be a router, etc. The communication device includes a housing, and the dual-band antenna can be arranged inside the housing.

[0058] The communication device provided by the utility model adopts the above-mentioned dual-band antenna, which includes a first antenna 10 and a second antenna 20 with different frequency bands. The first antenna 10 is a full-wave dipole antenna, which can enhance the basic gain of the high-frequency antenna, thereby improving the average gain of the horizontal plane. There is a guide opening 26 between the two second branches 21 of the second antenna 20. When working at a high frequency, the second antenna 20 is equivalent to a reflection strip for the first antenna 10. The setting of the guide opening 26 can weaken the reflection effect of the second antenna 20 in the high frequency band, so that the omnidirectionality of the directional diagram is better, and the average gain of the horizontal plane is improved. Moreover, by setting the feeding points of the first antenna 10 and the second antenna 20 at their corresponding antenna branches respectively, and not using a dual-band antenna with mode cancellation, the frequency band span of the dual-band antenna can be larger and not restricted by the mode.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual-band antenna, characterized in that: The invention comprises a first antenna and a second antenna which are arranged adjacent to each other, wherein the operating frequency of the first antenna is greater than the operating frequency of the second antenna, the first antenna is a full-wave dipole antenna, the first antenna comprises two first branches, and a first feeding point is located between the two first branches, the second antenna comprises two second branches, and a second feeding point is located between the two second branches, and a guiding opening is provided between the two second branches to reduce the reflection effect of the second antenna on the first antenna.

2. The dual-band antenna according to claim 1, wherein: The dual-band antenna has a symmetry line, which passes through the two first branches and the two second branches, and the first antenna and the second antenna are both symmetrically arranged about the symmetry line.

3. The dual-band antenna according to claim 1, wherein: The first branch has a first cutoff opening, so that the first branch is divided into a first microstrip line and a second microstrip line which are arranged at intervals, and two of the second microstrip lines are arranged adjacent to each other.

4. The dual-band antenna according to claim 3, characterized in that: A side of the second microstrip line close to the first feeding point has a first gap.

5. The dual-band antenna according to claim 4, characterized in that: The first slot extends along a length direction of the first antenna.

6. The dual-band antenna according to claim 3, characterized in that: One end of the second microstrip line close to the first microstrip line is the first end of the second microstrip line, the distance between the first ends of two second microstrip lines is a first dimension, the length of the leading opening is a second dimension, and the ratio of the first dimension to the second dimension is 0.7 to 1.

3.

7. The dual-band antenna according to any one of claims 1 to 6, characterized in that: A second slit is formed on one side of the second branch node close to the leading opening.

8. The dual-band antenna according to any one of claims 1 to 6, characterized in that: An end of the second branch away from the guide opening has a choke structure, the choke structure extends along the length direction of the second antenna, and a choke gap is formed between the choke structure and the second branch.

9. The dual-band antenna according to claim 8, characterized in that: An end of the second branch node close to the guide opening extends toward the choke structure to form an extension portion, and a side of the extension portion away from the choke gap is flush with a side of the choke structure away from the choke gap.

10. A communication device, characterized in that: The dual-band antenna comprises the dual-band antenna described in any one of claims 1 to 9.

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